The Spirit of Darkness
by darkworldprince
Summary: Take one part ancient immortal, another part Remnant, mix well and serve with a side of ancient relics. This is a story set in Remnant, with my oldest character and seeing what happens when i take him at full power, and dump him into the RWBY timeline, after all that's where he started originally. OP OC, Potential shipping later, more story based, M rated just in case.
1. Chapter 1

**_Foreword:_**

This is part of the story of Caius Yamigetsu, a character I created almost 6 long years ago, and he holds a very dear place in my heart. His original concept was very barebones, but then I found RWBY and his design fit just so well. I may write up some of the early days of his story (If i can find the old RP groups) but for now, I will demonstrate what 5 years of unforgiving RP groups of OP characters turned him into, any plot details I leave out progress the same way as in the show.

I do not own RWBY or any of the characters in the show. Thank you Roosterteeth and Monty Oum, Rest in peace, for creating a show that has become very dear to my heart.

**[Labs below Mountain Glenn, End of Volume 1]**

"We'll get it out of you somehow, even if we have to cut your tail off again" A hooded figure speaks to the chained up and bloody white haired man, with black horns protruding from his head along with a long black tail from his rear, who would look to be about 18 years old other than the white hair, with one other trait, in the middle of his purple eyes are pure white pupils, blind pupils.

"God dammit ya bastards... I told you all you need to know"

The hooded figure shakes their head.

"You assume we will free you when you're done, we will do no such thing. We had quite the hassle separating you from those swords you had with you, so as soon as you tell us what we wish to know you will die"

"Nah I won't. Here's what's going to happen, you're going to piss yourself and run out of here and I'm going to be completely safe from the Grimm behind this protective glass"

"Grimm? You have to be blind for real... What Grimm?!"

Caius nods his head past the hooded figure.

"Those Grimm"

The hooded figure turns and pales, and starts running from a horde of Beowulves giving chase, leaving an odd puddle on the floor, Caius smirks and just keeps hanging there laughing.

"Called it.. Wait how am I gonna get out of here?... They sealed up my powers..."

**[Still Mountain Glenn, Volume 2, Episode 9]**

"This way Yang! There's something down here, some kind of Lab" Blake calls to Yang, searching through the abandoned labs for something. She then hears something in the depths, a faint singing.

Yang walks over to her and chuckles.

"What's up kitty cat? Find something?"

"We may need the others, there's someone down there..."

Yang nods and after a quick call, Ruby, Oobleck, Weiss and Zwei join them.

"What is it you hear Miss Belladonna? There shouldn't be people here at all" Oobleck says quickly, proceeding first into the depths, with Zwei barking at his heels, and the deeper they get, the clearer the singing is.

"Twenty two thousand nine hundred and forty seven duel monster cards on the wall... twenty two thousand nine hundred and forty seven duel monster cards... take one down trade it a round and there's twenty two thousand nine hundred and forty six duel monster cards on the wall... Twenty two thousand nine hund- Who's there?!"

The team, teacher and dog emerge into the large room with the chained up guy behind the glass, a golden longsword in a tank to his left, and a black katana in a tank to his right, slashing about by itself trying to get out.

The five people on the outside of the glass share a look of confusion before Ruby answers.

"I'm... Ruby. I'm a huntress in training. This is my team.. and Professor Ooble-"

"Doctor! Doctor Bartholomew Oobleck." He interrupts.

"Nice to meet you, Doctor, and huntresses in training. Don't suppose you could let me out? I've been hanging here for months and I'm honestly starting to get a little hungry.." Caius replies with a sigh.

The five nod and set about trying to get the boy down, once he's down he does a lot of stretching and sighs.

"You cannot imagine what it's like hanging up there for months... I already made all the puns..."

Yang has a look of pure horror at the idea of running out of puns, she just pats him on the back, only to find that in addition to the horns and tail, there are two stumps on his back, from where wings have been cut off.

The four students of beacon and the teacher share the same thought at this revelation. What exactly is this guy?

Ruby crouches in front of him, going to look him in the eye. "So what's your na- Ah he's blind!" Ruby falls back on her butt, scrambling back and hugging Zwei in shock. Zwei barks and licks her face.

"My name is Caius Yamigetsu, and yes I am blind. But that does not make me useless."

Caius stands up and walks over to the tanks that have been sealing his weapons, and shattering the glass on each with a punch, the black katana flying straight into a sheath on his hip, he picks up the gold and sheathes it beside the black.

"I missed you too Yami-Ga. Don't worry"

He pats the black blade and walks back over to the group.

"We should probably get out of here before the Grimm come back... Right? I'll answer your questions once we're safe"

Ruby speaks again, after a nudge from Oobleck. "Well we have a camp above ground, we should wait there til morning, but we are here on a mission so..."

Caius nods. "I'll help ya with it, don't worry, I do owe ya for this one."

The group proceed out of the underground and up into their camp, Caius stands facing the horizon, inhaling the fresh air.

"God damn I missed this.."

Oobleck walks up beside Caius as the girls are cooking dinner for the group, or trying in Ruby's case, she seems more distracted by Zwei.

"You say you were trapped down there for months young sir?" Oobleck asks him.

"That is correct Doctor. My name is Caius Yamigetsu. As you can probably tell with your knowledge I'm neither Human nor Faunus"

"That is something I had indeed determined by examining you as we left the underground, however the reality of your species cannot possibly be... A reality"

"Well you do have a point there Doctor, but if you're thinking I'm some kind of Grimm you're wrong. I have a semblance, I have a pocket dimension I can open portals to from anywhere I've been, by opening two I can travel between those places."

"Then how do you explain the seeming lifelike state of that Katana? And this seemingly blind state of yours that is mirrored by the attitude of someone who sees clearly"

Caius smirks and turns to the Doctor, tilting his head.

"That is correct Doctor. I am Blind but that does not mean I cannot see. But how I do so is my secret."

"Very well young man, I shall now be getting some food and some rest, I advise you do the same"

Caius nods and goes with him back to the group.

**[Underground Train, Mountain Glenn, Volume 2 Chapter 11]**

"Get the humans!" A faunus yells at the group on top of the train, Caius having tagged along for the action, and aids them in fighting off the White fang members, a few moments later it is revealed that the Grimm will get into the City. As they run along the train Caius draws his Katana again, and with a quick batting of Zwei from Oobleck, Weiss, Yang, Blake and Caius drop into the train.

The first obstacle is Neo.

"You three go on ahead, this one's mine..." Yang says, and the other three run on. In turn getting met with a Chainsaw wielder.

Weiss calls out to the others. "You go on ahead" And stays behind to fight, as Blake is stopped by Torchwick, Caius drops back to help Weiss, to discover her mid fight against the Chainsaw nutjob, just as he grabs her by the mouth.

"Come here princess" He says and Caius jump kicks him in the back.

"Come here ugly!" And with a quick kick to the head, the chainsaw guy is knocked down, and Weiss stumbles back. Caius swaps out his Black blade for the Gold. "You wanna mess with the ice, you get some fire!" And with that he swings it, a flame coursing over the white fang member's back, badly wounding him enough for another kick to the head to knock him out.

"Thank you..." Weiss mutters before running off to help Blake, Yang Joins the three soon after, and the four go back to the roof since they have no idea how to stop the train, with a rock wall fast approaching.

**[Vale, Volume 2, Chapter 12]**

Team RWBY stands strong fighting off the Grimm, and as Caius swings his sword Grimm around him are ignited and fall to the flames extremely quickly. The rest of the fighters arrive fairly quickly to help finish off the Grimm, not the least the Atlas military robots, and the remainder of the fight progresses much the same way, and after Caius finds ruby throwing her cloak over him.

"Hey... Why?.."

"You don't want people questioning your looks do ya?"

"You have a point Ruby. Thank you"

Oobleck wanders over.

"I'm afraid he won't be needing it, he's coming with me back to Beacon, I informed the Headmaster of this particular predicament and he wishes to ask you about yourself, and of course, you must go with me, do you understand this Caius?"

Caius nods and hands the cloak back to Ruby, going with Oobleck and getting into a ship to Beacon with him.


	2. Chapter 2

**THE RISE AND THE FALL**

**[Ozpin's Office, Volume 3, Episode 1]**

"So you want me to become a student?" Caius says to Ozpin, stood facing him over the desk.

Ozpin nods in response. "That is correct. It would be the easiest way to, put simply, keep an eye on you"

"And for my team?"

"I will be putting you in with team RWBY for now, they are already aware of your situation"

Caius nods and turns as there's a knock on the door, it opens to reveal Ruby and Yang.

"You wanted to see me Professor Ozpin? We just arrived and Professor Oobleck told us"

"Doctor" Caius mutters absently, much as Oobleck would.

Ozpin stands and nods, walking around the desk to the three.  
"You two are already familiar with Caius i believe, as are your teammates, as of today I'll ask that you accept him as one of your team, there's not any other team at beacon who knows why he's here and I'd rather avoid questions."

Yang and Ruby nod and speak in unison. "Yes Sir"

Caius bows his head to Ozpin, and Ruby and Yang lead him off to their dorm, upon arrival Caius looks round, a little confused.

"So..." Caius starts "How are we gonna cram another bed in here?"

Yang grins and decides to tease him. "You're welcome to share mine!"

Caius rolls his eyes and pokes her head. "Down girl, I'll get a hammock."

Yang almost pouts, and goes off with Blake, leaving Caius alone with Ruby and Weiss.

"Why are we your team?" Weiss says, sounding annoyed. "We're a team of all girls, it's improper to have a man in here with us"

Caius sighs and sits by the window. "I'm as happy as you are Heiress. Ozpin's decree, you're the team who knows my circumstances"

"Aw don't be a sourpuss Weiss! Caius seems a good guy!"

"Ruby, we don't even know how he sees! What other secrets is he keeping?"

Caius sighs. "I am here, and i can hear you, I'm blind not deaf"

Weiss blushes softly and storms out. Caius sighs again and glances at Ruby.

"You wanna know how i do it?" He asks her calmly.

"How you see? Sure" She replies, sitting beside him.

"A long time ago, I was exiled from my home and left to rot in a cave, i was there for many years, so long my hair faded to white, and my eyes stopped working, i just didn't need them. But i learned something else in that darkness, how to see without mortal senses. Yes, I'm a demon. I have dark magic. I had it sealed whilst i was in that lab, but yeah... My vision is magical."

"That seems kinda like a copout..." Ruby says, patting his shoulder.

"Maybe Ruby, but sometimes the simplest solutions are the correct ones"

"Wait... That cave wasn't the lab so... How long were you chained up in the cave you went blind in?..."

Caius wiggles his fingers as he does some quick counting, then after a moment nods and calmly says, "A few million years", which only causes a look of pure shock from Ruby, who stands up and walks out to find her team, and tell them what she's learned.

**[Amity Coliseum, Volume 3, Episode 1]**

Caius sits in the audience, watching his new team perform in their fight against ABRN, applauding as they win their fight, and heading out to join them for lunch, walking up to them as they part ways with Emerald, passing by her and Mercury as he does.

"It's the heiress and the bimbo" She says to him, not really bothered by Caius.

Caius makes a personal note and sits up between Weiss and Blake. Not ordering a bowl of food, more there to just sit and listen, smirking as he watches Blake's unfolding relationship with the bowl of fish. And once JNPR leaves, he speaks.

"You know. I walked past your... uh... friend...? Emerald, on the way here. She was makin plans with her buddy with the weird boot sniffing thing."

"Oh!" Ruby says, smiling. "They seem nice! And so what if they know?"

Caius rolls his eyes. "Her exact words were 'Heiress and Bimbo' Ruby."

Yang's eyes turn red and Ruby looks a little crestfallen, but nods as Yang stands up to make after them, but Caius catches her wrist with surprising speed.

"Be calm, we'll show 'em up in the duo round. Good luck you two."

Weiss taps his shoulder and stands. "We should go and watch the fight, we can talk strategy later"

The five exchange nods and head off.

**[Beacon Courtyard, Volume 3, Episode 3]**

Weiss and Ruby run up to Winter as she arrives, greeting her in her dorky manner, Caius slowly walks toward them, just amused by the social interactions, and stopping as he sees something unusual. A very drunken man tearing the head off of one of the robots and confronting Winter. Qrow Branwen pushes Weiss aside and the air seems to drop a few degrees as he talks to Winter.

As the fight begins, Caius can only mutter "She's fast" before walking over to join Ruby and Weiss. "So this is what it looks like when two pros tussle?"

After a quick interruption by Ironwood and Ozpin, Qrow greets Ruby kindly.

"Qrow! Caius! A word please." Ozpin says, leading the two off to his office.

As the elevator doors open Winter and Ironwood are quick to jump to arms.

"What were you thinking!?" Winter yells.

Ironwood follows with "If you were one of my men, I'd have you shot!"

"If I was one of your men I'd shoot myself" Qrow responds, taking out his hip flask.

Ozpin gestures for Caius to come over as Glynda speaks with the two combatants, before speaking calmly. "Qrow, why are you here?"

"You've been out of contact for weeks!" Ironwood demands. "You can't just go dark like that in the field!"

"I'm not one of your special operatives Jimmy.."

Winter steps forward. "General."

"Whatever.. You sent me to get intel on our enemy, and I'm telling you, our enemy is here."

"...We know" Ironwood replies, sitting against Ozpin's desk, throwing a cautionary glance to Caius.

"Oh, oh you know? Well thank goodness I'm out there risking my life to keep you all informed!"

Ironwood sighs. "Qrow..."

"Communication is a two way street pal" He says, taking out his scroll. "You see this? That's the send button!"

"They had reason to assume you'd been compromised!" Winter starts, only to be interrupted.

"And I have reason to assume you don't need to be here. Seriously, who invited her? And him, why is a kid in this meeting?" He says, gesturing to Caius.

"Schnee, we'll discuss this incident back on my ship"

"But sir!.."

"Winter, leave."

Winter salutes and walks out, giving Qrow a dirty look, who in turn glances at Caius expectantly.

"Qrow, James" Ozpin starts. "This is Caius, he will need to be informed so he is going to stay for now."

Ironwood nods and turns to Qrow. "Go on.."

"Your little infiltrator isn't just another pawn, they're the one responsible for Autumn's condition..."

Caius sits and listens to the conversation, the back and forth between Ironwood and Qrow.

"Professor Ozpin... Why am I in this meeting?"

"Caius, as a demon you possess powers that could never be expected by our enemy, an ancient evil, Queen of the Grimm... Her name is-"

Caius interrupts saying the name calmly and drawing the attention of the room. "Salem..."

"How do you know that name?" Ironwood starts.

Caius shakes his head, Ozpin recognizing the sad look in his eye and holding a hand up. "You know who she is, I will find out how later. For now you must know that her forces are planning an assault on remnant"

Caius nods, and the meeting is concluded. "James, Qrow, Caius, we will discuss this further later, Caius, tell no one about this meeting"

"Of course Professor"

Ozpin nods, and Caius goes back to RWBY's dorm, watching the two girls play video games with their uncle, and smiling.


	3. Chapter 3

**AN DIA FALAMH**

**[Ozpin's Office, Volume 3 Chapter 6, Caius' Perspective.]**

"Well, it comes as no surprise that they've chosen you to move on to the final round of the tournament. Your performance has been exemplary."

Ozpin, Qrow and I are in his Ozpin's office. He's talking to that Pyrrha girl from team JNPR.

"Thank you Professor Ozpin but... I would never have made it this far without my teammates" She replies, but then Qrow pipes up.

"Personally I think it's the other way round" He seems in a worse mood than I've seen him in...

"I'm sorry, but I don't think we've been introduced" She says back to Qrow, standing and turning toward us.

"Name's Qrow, The blind punk is Caius"

Ozpin gives a slight cough before speaking.

"Qrow is a trusted colleague of mine, and Caius is a... new asset"

Pyrrha turns back toward him.

"Professor, if you don't mind me asking... Why have you called me here?"

There's an audible pause. Then Ozpin speaks. "Take a seat"

Pyrrha sits down, and Ozpin continues. I get the feeling this is gonna be interesting. There are a couple of stories listed... The Two Brothers and the Girl in the Tower sound familiar. Never heard of The Shallow Sea... And the story about The Four Maidens... Nice stories for children.

"...Winter, Spring, Summer and Fall, The Four Maidens." Pyrrha finishes. "My mother loves that story"

Ozpin seems to smirk, could just be a trick of the light...

"Would you believe me if I told you that one's been around since I was a boy?"

Pyrrha chuckles, it's a nice laugh. I'm surprised Jaune hasn't noticed her feelings since Pyrrha seems to wear them on her sleeve.

"You're not _that_ old, Professor.."

"Well.. Would you believe me if I told you it was true?"

I can't see Pyrrha's face from here, but I can almost feel her curiosity... Then she gives a forced chuckle.

"I.. Beg your pardon?.."

I step forward to listen to what Ozpin has to say. Magic... That explains why I'm here. There's a small exchange then a ding as the Elevator opens... And after a few moments we're in and going all the way down to the Vault...

I follow the group, walking beside Pyrrha. Glynda pauses to talk to her, and a conversation ensues as we walk, I stay silent and listen. And then we see her. The Maiden. Split power... Oh I'm starting to see where this is going... As the conversation continues, Qrow keeps drinking and Pyrrha keeps looking more scared. Until... She chooses to become The Fall Maiden, and the dangers get brought up. Could this kill her if it goes wrong?...

"...And there's no telling when their next move will be..." Ozpin finally finishes. "Caius, would you take her out to the Amity Coliseum? I believe the finals start soon"

"Yes Professor" I reply, nodding for Pyrrha to follow. "Cmon, guessing you have a lot on your mind?"

"How could I not? It's such a responsibility... Such a big secret"

"Maybe thinking of your favourite Blondie will help." I say with a smirk. Pyrrha turns as red as her dress when I say that.

"You certainly know the right thing to say to distract people"

"I try. Good luck in your fight when it comes up"

**[RWBY Dorm, Volume 3 Chapter 8]**

Yang's getting bollocked by Ironwood. After that punch to Mercury's leg... I know she didn't see it the same way as the rest of us. Unfortunately the word of an ancient, blind demon won't hold up in court.

There's an awkward silence as Ironwood leaves... And an argument. I take the chance to leave the room, waiting outside til they're done. Jaune pokes out of his dorm to talk to me.

"Hey Caius... Is she... Doing okay?" He asks, I could almost mistake him for her little brother now I think about it...

"She'll be okay man, things are just up in the air right now, yknow? The girls are having a talk so I left them to it..."

"If there's anything we can do, don't hesitate to ask" Ren says calmly, and I bow my head to him.

"Just make sure you bring home a win for beacon, Okay Pyrrha?" I say, smirking slightly.

"Of course, I'll do my best" She says, but the look on her face says she's still caught up in thought, I quickly grab Jaune and whisper to him before throwing him toward Pyrrha.

"She needs a hug, see you later" I then walk off down the hallway. I have a lot to research... Something isn't right.

A little while later as I walk past the cafeteria I spot Jaune and Pyrrha outside, having a conversation about destiny... I keep my distance and observe in silence, they don't seem to have noticed me... And Jaune got slammed into the wall... And Pyrrha's run off...

"What did I say..?" Jaune says quietly. I walk over and pat his shoulder.

"You said the right thing my friend. She needs a shoulder to cry on, and you are doing your best, but like you said. Don't. Give. Up."

Jaune nods and runs off, seeming a little surer of himself now, that's good. Now... a match should be starting soon.

As I arrive at the arena i hear the announcement. Penny versus Pyrrha... And as I round the corner I see the one with the broken leg... standing... talking to Ruby... They're not standing... They're about to fight and Ruby doesn't have her scythe! In a second I draw Yami-Ga and run to help.

**[Amity Coliseum, Volume 3 Chapter 9]**

The fight outside is about to start... After a quick skirmish, mostly trying to keep the kicks away from our faces, Ruby makes a getaway, leaving me with Mercury.

"So... I get to fight the lucky blind faunus?" He says, presumably noting on my horns and tail.

"I think you should start running..." I reply calmly, holding Yami-Ga ready. Then it happens. A wave of negative emotion... I can feel it so strongly... That can only mean one thing... Grimm.

The speakers activate, a voice, chilling. I hate monologues. And when it's over... Grimm. I need to get moving. I can help stop them.

I hold Yami-Ga ready and run outside, watching the Grimm. Then I speak calmly.

"Bare your fangs... Yami-Ga" My black sword seems to shiver as I speak, then shifts form, expanding from a katana to a scythe, black as darkness itself. Beacon is falling...


End file.
